The present invention relates to agricultural engineering and more specifically to pickups of agricultural machines.
The invention is applicable for picking from the ground various farm crops that have been mown down and either windrowed or spread.
A number of various pickups of agricultural machines are known to use in farm practice currently. The majority of these incorporate a pick-up-and-conveying mechanism driven from the agricultural machine it is teamed with, and a frame articulately suspended from said machine and resting upon the ground through the support wheels, said frame carrying said mechanism. To prevent the mass being picked from sweeping by wind and penetrating into the intake portion of the agricultural machine, a grate is provided on the pickup-and-conveying mechanism, said grate being, in a general case, essentially a beam fastened on the frame and a number of rods cantilevered to said beam in the direction of feed of the mass being picked. The grate can be either rigidly fixed on the frame or suspended therefrom articulately. In the latter case in order to restrict the downward turn of the grate, a number of levers are made fast on the beam, whereas provided on the frame are limit stops for said levers to rest against. The limit stops are as a rule made adjustable, e.g., as a bolt turned into the threaded hole in the frame and secured with a locknut so that the levers rest against the bolt head.
A disadvantage of the above-described rigid grate-to-frame fastening resides in that one cannot adjust the clear passage between the pickup-and-conveying mechanism and the rods to suit the weight and thickness of the windrow being picked.
A disadvantage of the above-described articulately suspended grate resides in the fact that the grate turning is restricted only in one direction (downwards), the grate might perform vibrating motion directed upwards, caused by vibration of the pickup while following the ground contour, with the result that the initially set clear passage is affected, whereby the direction of the discharge of the mass from the pickup-and-conveying mechanism is changed, and the intake end of the agricultural machine gets clogged.
A disadvantage of the cantilever arrangement of the grate rods resides in that the rods are liable to break at the places of their securing to the beam, this being due to reversal loads arising from the action of the mass being picked upon the rods and owing to constrained vibrations of the rods called forth by the vibration of the pickup.
Moreover, a disadvantage of the constructions described above consists in an inconvenient attendance of the pickup and the agricultural machine intake due to their being covered by the grate rods. Hinge-mounted grates can be swung aside to gain access to the intake of the agricultural machine but this results in that the grate rods cover the front portion of the pickup-and-conveying mechanism.
A constructional disadvantage of the afore-described adjustable restrictor is the fact that its adjustment changes the relative positions of the restrictor bearing surfaces (the bolt head) and of the lever, inasmuch as the lever turns about the grate suspension axis, whereas the restrictor moves translationally while being adjusted. As a result, a linear contact is usually liable to occur which brings about mutilation of the contacting surfaces.